This invention relates to product inspection methods and apparatus, and more particularly to methods and apparatus for optically determining whether or not a product has an acceptable appearance.
For many products such as consumer goods like packaged foods, beverages, cleaning products, health and beauty aids, cigarettes, cigars, etc., it is very important that the external appearance of the product or its packaging be uniform and defect-free. Yet these products are typically produced in such large quantities and at such high speeds that some form of automated optical inspection is practically essential. It is highly desirable for an optical inspection system to be able to test all or substantially all parts of the product image so that defects of any kind occurring anywhere in the image can be detected. At the same time the inspection system should not reject products having minor but acceptable deviations from the ideal product.
For even a relatively simple product image such as a cigarette pack, an inspection system must be initially supplied with a tremendous amount of information in order to enable the system to inspect all or substantially all portions of the image with the sophistication required to discriminate between acceptable products (i.e., products having the ideal appearance or an appearance acceptably close to the ideal) and unacceptable products which should be rejected because of defects in appearance or appearance which is not sufficiently close to the ideal. Identifying and entering this information into the inspection system apparatus typically requires a very high level of skill and/or large amounts of operator time. Moreover, this data identification and entry task must be repeated each time a new or even slightly different product is to be inspected.
It is therefore an object of this invention to improve and simplify optical inspection systems.
It is a more particular object of this invention to provide optical inspection systems which greatly reduce the level of operator skill and amount of operator time required to set up the system to inspect a new or different product.